supplementary materials

cis-Dibromidobis(2-phenylpyridine-N)platinum(II)

In the title complex, [PtBr2(C11H9N)2], the PtII ion has a distorted cis-Br2N2 square-planar coordination geometry defined by two N atoms from two 2-phenylpyridine (ppy) ligands and two Br- anions. The ppy ligands are not planar, the dihedral angles between the pyridine and benzene rings being 49.0 (3) and 47.3 (3)°. In the crystal, the complex molecules are stacked in columns along the a axis. In the columns, there are numerous intra- and intermolecular - interactions between the six-membered rings, the shortest ring centroid-centroid distance being 3.774 (6) Å.

The PtII ion in the title complex, [PtBr2(ppy)2], has a distorted
cis-Br2N2 square-planar coordination geometry defined by two N
atoms from two ppy ligands and two Br- anions (Fig. 1). The Pt—N and
Pt—Br bond lengths are nearly equivalent, respectively (Table 1). In the
crystal, the two pyridine rings are inclined to the least-squares plane of the
PtBr2N2 unit [maximum deviation = 0.092 (4) Å], making dihedral angles of
61.6 (2)° and 64.0 (2)°. The ppy ligands are not planar, the dihedral angles
between the pyridine and benzene rings being 49.0 (3)° and 47.3 (3)°. The
complex molecules are stacked in columns along the a axis. In the
columns, numerous intra- and intermolecular π-π interactions between the
six-membered rings are present, the shortest ring centroid-centroid distance
being 3.774 (6) Å (Fig. 2).

To a solution of K2PtBr4 (0.2391 g, 0.403 mmol) in H2O (20 ml)/MeOH (100 ml) was added 2-phenylpyridine (0.1810 g, 1.166 mmol) and stirred for 7 h at
room temperature. The formed brown precipitate was removed by filtration and
the solvent of the filtrate was evaporated. The residue was washed with H2O
and dried at 323 K, to give a yellow powder (0.1672 g). Crystals suitable for
X-ray analysis were obtained by slow evaporation from a CH3CN solution at
room temperature.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s.
planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor
wR and goodness of fit S are based on F2, conventional
R-factors R are based on F, with F set to zero for
negative F2. The threshold expression of F2 >
σ(F2) is used only for calculating R-factors(gt) etc.
and is not relevant to the choice of reflections for refinement.
R-factors based on F2 are statistically about twice as large
as those based on F, and R- factors based on ALL data will be
even larger.